Use of derivatives containing c-o-p bonds in patients with kidney failure

ABSTRACT

Use of a derivative attaining C-O-P bonds in a controlled release form to treat patients with kidney failure. Moreover, it comprises the use of said derivatives together with other active substances, which particularly may be selected from a list comprising a calcimimetic, vitamin, phosphate binder, thiosulfate, bisphosphonate, pyrophosphate, citrate, diuretic, antihypertensive and anticholesteraemic agent.

PRIORITY STATEMENT

This application is a non-provisional patent application claimingpriority to U.S. provisional patent application 61/791,090, filed onMar. 15, 2013, the entirety of which is incorporated by reference.

DESCRIPTION

The present invention relates to the use of a compound comprising C-O-Pbonds, in a prolonged release form, to treat diseases in patents withkidney failure, whether undergoing other treatments or not.

PRIOR STATE OF THE ART

Kidney failure (also known as renal impairment or kidney disease) is adisease that causes a progressive loss of kidney function, with aconcomitant decrease in the glomerular filtration rate (GFR) or index.Although the initial stages of kidney damage may be asymptomatic,uraemia presents as the disease progresses. Uraemia is a concept thatdescribes the contamination of blood due to incorrect filtration andelimination of toxins by the kidneys.

Kidney disease can be classified as:

-   -   Acute kidney injury: a progressive loss of kidney function,        which generally causes oliguria and a fluid and electrolyte        imbalance. Treatment by dialysis may be necessary until the        causes of the disease can be identified and treated.    -   Chronic kidney disease (CKD): a much slower loss of kidney        function over a period of months or years. Depending on the        degree of kidney function, five stages of CKD are defined on the        basis of the GFR:        -   Stage 1: normal or high GFR (>90 ml/min)        -   Stage 2: Mild CKD, GFR=60-89 ml/min        -   Stage 3: Moderate CKD, GFR=30-59 ml/min        -   Stage 4: Severe CKD, GFR=15-29 ml/min        -   Stage 5: Terminal CKD, GFR<15 ml/min. Dialysis or a kidney            transplant are required to maintain the state of health.            Moreover, it is possible that acute renal failure may occur            concomitantly with CKD, which is known as acute-on-chronic            renal failure.

Patients who suffer said condition are treated with differenttherapeutic alternatives. Amongst other functions, the kidneys areresponsible, together with the liver, for activating vitamin D (vitD),which plays an important role in calcium homeostasis. Patients withrenal impairment therefore present a vitD deficiency and, as a result,this is the first pharmacological treatment to be introduced.

Renal impairment, together with treatment of the disease, leads tohypercalcaemia and hyperphosphataemia. Consequently, patients withkidney failure are treated with phosphate binderphosphate binders toreduce the phosphate concentration in blood and calcimimetics to controlthe calcium levels in plasma by controlling parathormone (PTH) levels.The phosphate binderphosphate binders described include sevelamer andvarious salts lanthanum, iron, calcium and other metals. The maincalcimimetics are cinacalcet and KAI-4169.

Moreover, other types of co-medications that are administered in renalimpairment to regulate blood pressure, cholesterol, diuretic use, sodiumthiosulfate or bisphosphonates also exist.

Hypercalcaemia and hyperphosphatemia may cause cardiovascularcalcification, although a deficiency of repressor factors (such asmatrix Gla protein, osteopontin, fetuin, vitamin K) or an imbalance inpromoting factors (vitamin D, FGF23, inflammatory cytokines, lipiddeposits, apoptotic bodies, nucleational complexes, etc.) may delay oraccelerate the process. Patients with renal impairment are commonlydescribed as patients with CKD-MBD (chronic kidney disease—mineral bonedisease) as altered kidney function provokes a cascade of effects thatalso affect bone remodelling.

It has been shown that the degree of coronary artery calcification isrelated to lower survival and a higher number of cardiovascular events(R S Shantouf, M J Budoff, N Ahmadi, A Ghaffai, F Flores, A Gopal, NNoon, J Jing, C P Kovesdy, K Kalantar-Zadeh. Total and individualCoronary Artery Calcium Scores as Independent Predictors of Mortality inHemodialysis Patients. Am J Nephrol 2010; 31:419-425).

Specifically, it was shown that patients with no measurable coronaryartery calcification (CAC=0) present a lower percentage ofcardiovascular events and a lower mortality. As the CAC score increases,the number of cardiovascular events also increases and survivaldecreases.

Moreover, Russo et al. (D Russo, S Corrao, Y Battaglia, M Andreucci, ACaiazza, A Cariomagno, M Lamberti, N Pezone, A Pota, L Russo, M Sacco, BScognamiglio. Progression of coronary artery calcification and cardiacevents in patients with chronic renal disease not receiving dialysis.Kidney Int 2002; 80:112-118) demonstrated that a faster progression ofvascular calcification is correlated with a lower survival and higherrisk of cardiovascular accidents.

As such, cardiovascular events, including death, are related to bothparameters:

Degree of vascular calcification.

Speed of progression of said vascular calcification.

There are currency no approved therapies which have demonstrated ahigher survival or lower cardiovascular accident rate in dialysispatients, and the need to treat different diseases associated with renalimpairment, resulting from the calcification process in the body and animbalance in bone remodelling, remains.

Various compounds the structure of which contains phosphorus(pyrophosphate, bisphosphonates, inositol phosphates, hexametaphosphate,etc.) have been repotted to inhibit the formation of calcium-containingcrystals. Some of the compounds in this large family containing C-O-Pbonds have been found to inhibit various types of calcification,although it has not yet been demonstrated that these therapies areuseful in the presence of renal impairment as known studies have eitherbeen with normal kidney function or, in the case of uraemia, saidcompounds have not been found to be effective.

DESCRIPTION OF THE INVENTION

Unexpectedly, the inventors of the present invention have found a formfor prolonged administration in individuals with kidney failure thatallows the efficacy of compounds of formula I, which would otherwise notbe effective in individuals with uraemia, to be re-established. Saidprolonged administration contrasts with a bolus- or short infusion-typeadministration and allows adequate levels of these compounds to bemaintained or even re-established in blood for an adequate period oftime. As a result, the kidney damage-related diseases are prevented,treated, inhibited and/or mitigated, or the progression thereof isprevented, in either the early stages of said diseases or when they arealready established.

Thus, one embodiment of the present invention relates to use of at leastone compound of formula I, or a pharmaceutically acceptable saltthereof:

where:

each of R₁ to R₁₂ independently represents H, —X, —OX, —NHX, —NX₂, —SX,—OSO₃HX, —OSO₃X₂ or a compound of formula II:

where each X independently represents H, C₃₋₃₀alkyl, C

alkenyl, C₂₋₃₀alkynyl or Cy

, where C

alkyl, C

alkenyl and C₂₋₃₀alkynyl are independently optionally substituted withone or more R₁₄ and where Cy

is optionally substituted by one or more R₁₅:

Cy₁ represents a carbocyclic or heterocyclic three- to 10-membered ring,which may be saturated, partially unsaturated or aromatic, where saidheterocycle has between one and four heteroatoms selected from amongstO, S and N, where said ring can be bound to the rest of the molecule viaany available C atom and where Cy₁ is optionally fused to between oneand four five- or six-membered rings, each saturated, partiallyunsaturated or aromatic, carbocylic or heterocyclic, and where saidfused heterocycle may contain one or two heteroatoms selected fromamongst O, N and S; each R₁₃ independently represents H, C₃₋₃₀alkyl,—NH₂, —NHC₁₋₃₀alkyl or N(C₃₋₃₀alkyl)₂, where each C₂₋₃₀alkyl isindependently optionally substituted with one or more halogen, —OH, —CNand —NO₂ groups; and

each R₁₄ and R₁₅ independently represents —OH, C₁₋₃₀alkoxy, C

alkylthionyl, C

acyloxy, phosphate, halogen, trihaloC

alkyl, nitrite or aside,

with the condition that at least one of R₁ to R₁₂ independentlyrepresents a compound of formula II, for the manufacture of a medicamentfor the treatment of a kidney failure-related disease in a subject withkidney failure characterised in that said medicament is administered ina prolonged release form.

In another embodiment the invention relates to the use defined above,where: Each X preferably independently represents H, C₁₋₃₀alkyl or Cy₁,where C₁₋₃₀alkyl is optionally substituted by one or more R₁₄ and whereCy₁ is optionally substituted by one or more R₁₅; and

each R₁₄ and R₁₅ independently represents —OH, C₁₋₃₀alkoxy, C

alkylthionly, C

acyloxy, phosphate, halogen, trihaloC

alkyl, nitrite or azide.

In another embodiment the invention relates to the use defined above,where: each X represents H, C₁₋₃₀alkyl or Cy₁.

In another embodiment the invention relates to the use defined above,where: each X represents H.

In another embodiment the invention relates to the use defined above,where: At least one of radicals R

, R

, R

, R

, R

and R

independently represents a compound of formula II:

each R

independently represent H, C

alkyl, —NH₂, —NHC

alkyl, or —N(C

alkyl)₂, where each C

alkyl is independently optionally substituted by one or more halogen,—OH, —CN and —NO₂ groups; and R

, R

, R

, R

, R

and R

independently represent H.

In another embodiment the invention relates to the use defined above,where: R

, R

, R

, R

, R

and R

independently represent a compound of formula II:

each R

independently represents H or C

alkyl, where each C

alkyl is independently optionally substituted by one or more halogen,—OH, —CN and —NO₂ groups; and R

, R

, R

, R

, R

and R

independently represent H.

In another embodiment the invention relates to the use defined above,where: R

, R

, R

, R

, R

and R

independently represent a compound of formula II:

each R

independently represents H or C

alkyl; and R

, R

, R

, R

, R

and R

independently represent H.

In another embodiment the invention relates to the use defined above,where: R

, R

, R

, R

, R

and R

independently represent a compound of formula II:

each R

independently represents H; and R

, R

, R

, R

, R

and R

independently represent H.

In a further embodiment the invention relates to the use defined above,where the compound of formula I is inositol hexaphosphate (IP6).

Inositol phosphate can form other inositol phosphates (IP5, IP4, IP3,IP2, IP1 or inositol) by dephosphorylation in vivo. Inositol is assumedto mean any isomeric form of the molecule.

All compounds of formula I contain C-O-P bones. Said bond provides saidcompounds with an affinity for calcium-containing crystals and asufficiently labile bond to be hydrolysed in vivo, thereby preventingirreversible binding to calcium-containing crystals such as thehydroxyapatite (HAP) in bone, which would have a negative impact on boneremodelling, as is the case with bisphosphonates when administered longterm as said compounds contain P-C-P bonds that cannot be hydrolysed bythe body.

At the other extreme are phosphorylated compounds that do not containsaid C-O-P bonds, such as pyrophosphates, the P-O-P bonds of which meanthat they are too readily hydrolysed in the intestine, thus meaning thatonly parenteral administration is feasible.

The compounds of the present invention, with C-O-P bonds, represent anadequate midpoint due to the efficacy thereof and the fact that the bodypresents mechanisms for eliminating said compounds, thus reducing therisk of side effects.

In this sense, the inventors have demonstrated that said compounds bindrapidly to their receptor, thereby allowing the compound to achievemaximum binding in a relatively short period of time, and that saidbinding is reversible, thus meaning that the compound can be eliminatedfrom the surface of the receptor over a reasonable period of time. Thisfact represents an enormous difference with regard to compounds withP-C-P bonds, which in vivo may present half-lives of several months onthe surface of their receptor, for example in bone, thereby affectingbone remodelling.

In another embodiment the invention relates to the use defined above,which also comprises a compound selected from amongst a calcimimeticcompound; vitamin B, vitamin D and vitamin K; phosphorus (phosphate)chelators; thiosulfate, a diuretic, preferably thiazide or indapamide;bisphosphonate or a pharmaceutically acceptable salt thereof;pyrophosphate; citrate, an antihypertensive and anticholesteraemicagent.

The diuretic compounds preferably include thiazide or indapamide.

In another embodiment the invention relates to the use defined above,which also comprises vitamin D and/or K.

Throughout the present invention, the term “C

alkyl”, as a group or part of a group, refers to a linear or branchedchain alkyl group containing between 1 and 30 carbon atoms including,amongst others, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl, tert-butyl, pentyl, hexyl, decyl and dodecyl groups.

The term “C

alkenyl” refers to a linear or branched alkyl chain containing between 2and 30 carbon atoms and also contains one or more double bonds. Examplesinclude, amongst others, ethenyl, 1-propenyl, 2-propenyl, isopropenyl,1-butenyl, 2-butenyl, 3-butenyl and 1,3-butadienyl.

The term “C

alkynyl” refers to a linear or branched alkyl chain containing between 2and 30 carbon atoms and also contains one or more triple bonds. Examplesinclude, amongst others, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl,2-butynyl, 3-butynyl and 1,3-butadiynyl.

A Cy₁ group relates to a three- to 10-membered carbocyclic orheterocyclic ring that may be saturated, partially unsaturated oraromatic and which is bound to the rest of the molecule via anyavailable C atom. When heterocyclic, Cy₁ contains between one and fourheteroatoms selected from amongst N, O and S. Moreover, Cy₁ mayoptionally be fused with up to four five- or six-membered carbocylic orheterocyclic rings, which may be saturated, partially unsaturated oraromatic. If the fused ring is a heterocycle, said ring contains one ortwo heteroatoms selected from amongst N, O and S. Examples of Cy₁include, amongst others, phenyl, naphthyl, thienyl, furyl, pyrrolyl,thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, 1,2,3-triazolyl,1,2,4-triazolyl, triazolyl, 1,3,4-thiadiazolyl, 1,2,4-thiadiazolyl,pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzimidazolyl,benzofuranyl, isobenzofuranyl, indolyl, isoindolyl, benzothiophenyl,benzothiazolyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cycloheptyl, azetidinyl and aziridinyl.

A C

alkoxy group as a group or part of a group refers to an —OC

alkyl group, where the C

alkyl part has the same meaning as above. Examples include methoxy,ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy andtert-butoxy.

A C

alkylthionyl group as a group or part of a group refers to an —SOC

alkyl group, where the C

alkyl part has the same meaning as above. Examples includemethyithionyl, ethylthionyl, propylthionyl, isopropylthionyl,butylthionyl, isobutylthionyl, sec-butylthionyl and tert-butylthionyl.

A C

acyloxy group as a group of part of a group refers to a —COC

alkyl group, where the C

alkyl part has the same meaning as above. Examples include acetyl,ethanoyl, propanoyl and 2,2-diisopropylpentanoyl.

A halogen radical or the halo abbreviation thereof refers to fluorine,chlorine, bromine and iodine.

A trihaloC

alkyl group signifies a group resuming from the substitution of threehydrogen atoms of a C

alkyl group by three halogen radicals as defined above. Examplesinclude, amongst others, trifluoromethyl, tribromomethyl,trichioromethyl, triodomethyl, trifluoroethyl, tribromoethyl,trichloroethyl, triiodoethyl, tribromopropyl, trichloropropyl andtriiodopropyl.

An —NH

alkyl group signifies a group resulting from the substitution of onehydrogen atom of an —NH₂ group by a C

alkyl group as defined above. Examples include, amongst others,methylamine, ethylamine, propylamine, butylamine and pentylamine.

—N(C

alkyl)₂ signifies a group resulting from the substitution of twohydrogen atoms of an —NH₂ group by a C

alkyl group as defined above. Examples include, amongst others,dimethylamine, diethylamide, diisopropylamine, dibutylamine anddiisobutylamine.

The expression “optionally substituted by one or more” signifies thepossibility that a group may be substituted by one or more, preferablyby 1, 2, 3 or 4 substituents, more preferably by 1, 2 or 3 substituentsand even more preferably by 1 or 2 substituents provided said group hassufficient positions that can be substituted available. If present, saidsubstituents may be the same or different and may be located at anyavailable position.

A further aspect of the present invention relates to use of acomposition comprising at least one compound of general formula I asdescribed above and another active substance and/or a pharmaceuticallyacceptable vehicle.

The active substance is selected from the list comprising acalcimimetic, vitamin, phosphate binder, thiosulfate, bisphosphonate,pyrophosphate, citrate, a diuretic, antihypertensive andanticholesteraemic agent to manufacture a medicament for the treatmentand/or prevention of a kidney failure-related disease in a subject withkidney failure characterised in the said medicament is administered in aprolonged release form.

Said compounds are normally used to treat kidney damage-relateddiseases. CKD-MBD always has a calcium and phosphorus metabolismimbalance, which results in hypercalcaemia and hyperphosphataemia, as anunderlying problem and there comes a stage when bone, which mainlyconsists of HAP (calcium phosphate), can no longer act as a buffer forsaid excess calcium and phosphorus in the blood, thus meaning thatcalcium-containing crystals are deposited in different tissues andorgans in the body. As a result, the different drugs in the previousparagraph act at different levels but with a single objective, namely tohelp control said calcium and phosphorus metabolism imbalance.

Several of the compounds described as active substances change thethermodynamics of the crystallisation process by modifying theconcentration of the ions present in the structure of thecalcium-containing crystal that is directly or indirectly responsiblefor the kidney failure-related disease. This sub-group includescalcimimetics, phosphate binder, thiosulfate, vitD and diuretics.

Calciminetics allow the calcium and phosphate concentration to becontrolled by regulating blood PTH levels. Said compounds includecinacalcet, NPS R-467, NPS R-568, KAI-4169.

Thiosulfate is a chelator that reduces the free calcium concentration inblood.

Although with a different mechanism of action, vitD has a similareffect. The vitD is preferably selected from the list comprisingcalciferol, ergocalciferol (Vit D2), cholecalciferol (Vit D3),doxercalciferol, paricalcitol, alfarol or alpha-calcidol, calcidiol,calcitriol, or derivatives or pharmaceutically acceptable salts thereof.

Phosphate binders act gastrointestinally by sequestering phosphatsbefore it can be absorbed, thereby reducing the systemic concentrationthereof in blood. The phosphate binder may contain a metal or bemetal-free. The metal-free chelators include sevelamer. Metal-containingchelators include various calcium, iron, lanthanum, aluminium andmagnesium salts.

Diuretics also affect the thermodynamics as altering the volume changesthe calcium and phosphate concentration. The diuretic will preferably bea thiazide, thiazide-like (indapamide, chlortalidone, metolazone, etc.),a loop diuretic (bumetanide, etacrynic acid, furosemide, torsemide,etc.), carbonic anhydrase inhibitor, osmotic diuretic, potassium-sparingdiuretic, etc. The thiazide will preferably be chlorothiazide,epithiazide, bendroflumethiazide or hydrochlorothiazide.

The remaining compounds (pyrophosphate, citrate, bisphosphonates,antihypertensives, anticholesteraemic agents, vit B, vit K) act againstthe altered calcium and phosphate metabolism kinetically by attemptingto stop the crystallisation process or altering bone metabolism byincreasing the amount of repressor factors (pyrophosphate, citrate, vitB, vit K, bisphosphonates) or by reducing the quantity of promoterfactors (necrotic remains or organic matter in the case ofantihypertensives or lipid deposits in the case of anticholesteraemicagents).

The bisphosphonate may contain nitrogen or be nitrogen-free. Saidbisphosphonate will preferably be selected from the list comprisingetidronate, alendronate, risedronate, zoledronate, tiludronate,pamidronate, monidronate, neridronate, pamidronate, olpadronate,clodronate, ibandronate.

The antihypertensive will preferably be a diuretic (listed above), anadrenergic blocker (beta blocker, alpha blocker, mixed), a calciumchannel blocker (dihydropytidine or non-dihydropyndine), a renininhibitor, an angiotensin-converting enzyme inhibitor, an angiotensin IIreceptor antagonist, an aldosterone antagonist, a vasodilator, analpha-2 agonist or a blood pressure vaccine.

The anticholesteraemic agent will preferably be a statin, a fibrate,niacin, a bile acid sequestrant, ezetimibe, lomitapide, phytosterols ororlistat.

In another embodiment the invention relates to a combined compositioncomprising at least one compound of formula I as defined above and oneor more useful drugs for use thereof alone, simultaneously orsequentially for the treatment of patients with kidney failure,preferably where the useful drugs are selected from amongst acalcimimetic, vitamin B, vitamin D and vitamin K, phosphate binder,diuretics or other such as a bisphosphonate or a pharmaceuticallyacceptable salt thereof, pyrophosphate, citrate, antihypertensive oranticholesteraemic agent.

In this report, the term “combined preparation” or “juxtaposition”signifies that the components of the combined preparation do not need tobe present together, for example in a composition, such that saidcomponents may be available for application separately or sequentially.Consequently, the expression “juxtaposed” implies that said preparationis not necessarily a true combination in light of the physicalseparation of the components thereof.

The pharmaceutical composition of the invention may also comprise one ormore excipients.

The term “excipient” refers to a substance which helps absorption of theelements of the pharmaceutical composition of the invention, stabilisessaid elements, activates or helps preparation of the composition in thesense of conferring consistency or providing flavours that make saidcomposition more palatable. Thus, the excipients may have a rolemaintaining the ingredients combined, such as starches, sugars orcelluloses for example, as a sweetener, as a colourant, protecting thecomposition, such as isolating it against air and/or moisture, as afiller for a tablet, capsule or any other presentation, as adisintegrant to ensure dissolution of the components and absorptionthereof in the intestine, without excluding any older type of excipientnot mentioned in this paragraph.

As is the case for the excipient, the “pharmaceutically acceptablevehicle” is a substance used in the composition to dilute any of thecomponents contained therein to a determined volume or weight. Thepharmaceutically acceptable vehicle is an inert substance or a substancewith an analogous action to any of the elements comprising thepharmaceutical composition of the present invention. The role of saidvehicle is to allow the incorporation of other elements, allow betterdosing and administration or to provide consistency and shape to thecomposition.

A further aspect of the present invention relates to a method fortreating patients with kidney failure comprising the administration of aprolonged release (non-bolus) form a therapeutically effective amount ofa compound of formula I or a pharmaceutically acceptable salt thereof.

In the present invention, the term “kidney failure-related disease”refers to disease processes of a widely diverse nature in individualswith kidney damage and may refer, but is not limited, to any diseaserelated to calcium or calcium metablish disorders, such as renallithiasis, cardiovascular calcification, cardiovascular disease,osteoporosis, bone cancer, podagra, calcific tendinitis, calcinosiscutis, rheumatoid arthritis, bone mineral disease, osteomalacia,adynamic bone, calciphylaxis.

Other kidney failure-related diseases may be of the cardiovascular type,such as, but not limited to, coronary dtsease, heart failure, cardiacdisease, atherosclerosis, arteriosclerosis, thrombosis, hypertension,myocardial infarction, aneurysm, engine pectoris, peripheral vasculardisease and cerebrovascular disease. The patient with renal impairmentmay suffer a cardiovascular accident, event or disease (ischaemia,arrhythmia, myocardial infarction, stroke, etc.).

An important concept is that various disorders, including those listedin the previous paragraphs, may be treated by preventing, reducing,slowing or stopping the progression of calcification in the presence ofuraemia. The disease related to calcium disorders, or the calcificationinduced by said disease, may already be present when administrationcommences, in order to reduce or stop progression of the disease, or maynot yet be present, in order to prevent the appearance or onset of thedisease.

In the present invention, the term “kidney failure” or “renalimpairment” refers to a subject with diminished kidney function (GFR) inany of stages 1 to 5 thereof, with acute kidney injury oracute-over-chronic renal failure.

In the present invention, the term individual or subject refers to anyanimal species, including humans.

In the present invention, the term “prolonged release”, slow release,non-bolus, refers to an administration form that slowly releases thecompound into the bloodstream, thus allowing significant levels to bemaintained in plasma for a longer period of time than for a “bolus-type”administration. A bolus-type administration comprises fast intravenousinjection, for example less than 10 seconds, or intravenous infusionover less than approximately 3 minutes.

In an embodiment of the present invention, the prolonged release allowstherapeutically adequate levels to be maintained in blood for at least30 minutes. In the case of inositol phosphates, said adequate levelswill preferably be higher than 0.15 micromolar (μM), more preferablyhigher than 0.3 μM and even more preferably higher than 0.6 μM.

The inventors have unexpectedly discovered, and with comparative tests,that the efficacy of treatment for vascular calcification that can beachieved under conditions of normal kidney function disappears when thesubjects present renal impairment (uraemia). Consequently, it isdescribed for the first time that a non-bolus type administration toachieve adequate therapeutic levels and maintain said levels for anadequate period of time is particularly useful and also allows the sideeffects to be reduced, thereby improving the safety profile of theproduct. Said non-bolus administration can be given in a period of 24hours, preferably in a period of 4 hours, more preferably in a period of20 minutes and even more preferably in a period of 5 minutes. In anycase, although administration occurs over a short period of time, themost important aspect is that release of the compound into the blood isprolonged in time, of the non-bolus type, and should allow therapeuticlevels to be maintained in blood for at least 30 minutes, preferably formore than 1 hour, more preferably for more than 3 hours and even morepreferably for more than 4 hours.

An important aspect of the present invention consists of the treatmentof subjects with renal impairment to prevent or treat a calciumdisorder-related disease. Although compounds with C-O-P bonds have beendescribed to inhibit the crystallisation of calcium-containing salts,the use thereof in subjects with renal impairment and as a non-bolustype administration is novel. For example, inositol hexaphosphate (IP6)has been described for the treatment of kidney stones in rats withnormal kidney function (F Grases, B Isern, P Sanchis, J J Torres, ACosta-Bauzà, A. Phytate acts as an inhibitor of renal calculi. FrontBiosei 2001; 12:2580-2587), but the effect thereof on kidney stoneformation in subjects with renal impairment has never been demonstrated,with said use being completely novel. Various recent attempts todemonstrate the efficacy of such compounds in calcium disorder-relateddiseases in the presence of uraemia have failed, leading to theconclusion by persons skilled in the art that such compounds are notuseful for treating said diseases in the presence of renal impairment.

The inventors have unexpectedly discovered that when compounds withformula I, containing C-O-P bonds, are administered to animals withuraemia, much lower levels in blood are achieved and for a shorterperiod of time. This finding contrasts completely with the understandingof a person skilled in the art. When a compound is administered underconditions of renal impairment, renal elimination of said compound isreduced when compared with the case of normal kidney function, with moresevere renal dysfunction leading to slower elimination of said compound.Consequently, a person skilled in the art would expect that when acompound is administered to a subject with renal impairment, higherlevels of said compound in blood would be obtained tor a longer periodof time in comparison with a subject with normal kidney function.

Unexpectedly, the inventors discovered that the behaviour of thecompounds of formula I is exactly the opposite. The recent developmentof adequate analytical tools has allowed this surprising behaviour to bediscovered (Perelio J, Maraschiello C, Lentheric I, Mendoza P, Tur F,Tur E, Encabo M, Martin E, Benito M, Isern B. Method for the directdetection and/or quantification of at least one compound with amolecular weight of at least 200. PCT/EP2012/069878) as previous methodsdid not allow such compounds to be correctly quantified in biologicalmatrices such as blood.

When a compound of formula I is administered to a subject, lower levelsof said compound in blood or plasma are obtained, and in some cases saidlevels are undetectable. Administration of the same dose via the sameroom of administration to a subject with normal kidney function leads tohigher levels in blood for a longer period of time.

The inventors discovered that elimination of said compounds in thepresence of uraemia is much faster due to the greater metabolism of thecompound. This finding explains why various attempts to demonstrate theefficacy of such compounds in the presence of uraemia failed as thecompound was rapidly destroyed (metabolised), more so than underconditions of normal kidney function, and could not exert itstherapeutic effect on the specific receptor and disease, in other words,the higher metabolic rate prevented therapeutic levels from beingreached and maintained for a sufficient time to demonstrate efficacy.

The compounds or compositions of the present invention may beadministered by any appropriate method that provokes a non-bolus typerelease or effect, such as intravascular (for example intravenous)infusion, other parenteral (subcutaneous, subcutaneous depot,intraperitoneal, intramuscular, intradermal, intrathecal, epidural,spinal or others known to a person skilled in the art), topical(intranasal, inhalation, intravaginal, transdermal or others known to aperson skilled in the art), enteral (oral, sublingual, rectal, etc.)administrations, oral, spinal, intraperitoneal preparations or othersknown to a person skilled in the art.

In the particular case of oral administration, delivery technologies maybe used to achieve higher levels in blood or to maintain said levels fora longer period of time in order to achieve or enhance the prolongedrelease (non-bolus) effect. As examples, said delivery techniques mayinclude the use of liposomes, organic polymers, the formation ofassociations or ion pairs (for example quaternary ammonium salts).Additionally, delivery technologies may delay or modulate absorption ofthe compound and/or protect said compound from being metabolised in thegastrointestinal tract or during first hepatic pass prior to reachingthe bloodstream and/or corresponding receptor, which may help tomaintain exposure over time.

In the particular case of patients treated with dialysis, a veryappropriate method of administration consists of a non-bolus typeadministration of the compound via the dialysis apparatus (before orafter the filter) instead of directly injecting the compound into thepatient intravenously. Thus, blood can be treated with the compound asit leaves the patient and circulates through the dialysis circuit and,when the blood containing the compound returns to the body, the compoundhas been introduced into the blood in a manner that presents a series ofadvantages.

This method of administration was unexpectedly discovered as a plausiblealternative. A person skilled in the art would undoubtedly have thoughtthat administration via the dialysis apparatus would not be possible asthese compounds with a relatively low molecular weight should readily belost via the dialysis membrane. Consequently, administering the compoundvia the dialysis system when the blood is outside the body would not bean alternative as the compound would be lost (dialysed) when passingthrough the filter (dialysis membrane) prior to reaching the body of thesubject again. In the case of IP6, for example, the inventorsunexpectedly found that said compound is not lost as it was discoveredthat binding of IP6 to proteins was in the range 70-90%, thus meaningthat only 10-30% of the compound is available to be dialysed. However,and in addition, the high negative charge of the compound creates anelectrostatic repulsion that prevents the passage thereof through thefilter in a significant manner.

Moreover, the inventors showed that said compounds, preferably inositolphosphates, can chelate (sequester) free or ionic calcium in thebloodstream, thereby reducing the concentration thereof, which isnecessary for said calcium to perform its biological role. Thus, calciumchelation is a problem when certain blood concentrations are reached. Anon-bolus type administration is much more appropriate as saidadministration avoids concentration peaks and the effect on calciumchelation is eliminated.

Moreover, in the case of dialysis patients, administration via thedialysis apparatus allows the blood to equilibrate with the dialysisfluid prior to returning to the body; thus, although the compoundcontaining C-O-P bonds may sequester ionic calcium, this fact iscompensated when the blood passes through the dialysis filter, therebyeliminating said side effect and significantly improving the safetyprofile.

As used in the present invention, the term “treatment” refers tocountering the effects caused as a result of the disease or pathologicalcondition of interest in a subject (preferably a mammal, and morepreferably a human), including:

(i) inhibiting the disease or pathological condition, in other wordsslowing or stopping the development or progression thereof;

(ii) relieving the disease or pathological condition, in other wordscausing said disease or pathological condition, or the symptoms thereof,to regress;

(iii) stabilising the disease or pathological condition.

In an embodiment of the present invention, a synergistic effect isunexpectedly observed between a compound of formula I and othertreatments for renal impairment selected from the list, as it has beenobserved that when a compound of formula I is combined with another thatmodifies the thermodynamics of the calcium-containing crystal formationor growth process a synergistic effect occurs. Moreover, it has beenobserved that combining a compound of formula I with another compoundthat modifies the kinetics of said process (reducing the promoterfactors or increasing the repressor factors) also produces said synergy.

In general, the effective quantity of a compound of the inventionadministered will depend on the relative efficacy of the compoundconcerned, the severity of the disorder treated and the weight of thesubject. Administration can range from daily to weekly, monthly, twomonthly or any other frequency known to a person skilled in the art.

The word “comprises”, and variants thereof, as used throughout thedescription and claims, is not intended to exclude other technicalfeatures, additives, components of steps. For a person skilled in theart, other subject matters, advantages and features of the inventionwill partially follow from the description and partially from thepractice of the invention. The following examples and drawings areprovided by way of illustration and are not intended to limit thepresent invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Adsorption of IP6 to different concentrations of HAP crystalsafter incubation at 37° C., pH 7.4, for 8 h.

FIG. 2. Adsorption of IP6 to HAP crystals. IP6 (7-6 μM) was incubated inthe presence of 130 mg HAP at 37° C., pH 7.4, for between 5 minutes and8 hours.

FIG. 3. Release kinetics of IP6 from the HAP surface. IP6 (7.6 μM) wasincubated in the presence of 130 mg HAP and IP6 released at differenttimepoints up to 48 hours.

FIG. 4. PK profile for IP6 after s.c. administration of 10 mg/kg innormal and uraemic rats.

FIG. 5. PK profile for IP6 after intravenous infusion of 10 and 50 mg/kgin normal and uraemic rats for 4 h.

FIG. 6. Calcium content in aorta (A) and heart (B) after intravenousadministration of IP6 in a vitamin D-induced cardiovascularcalcification model in rat (5×75,000 IU/kg). Dose expressed in mg/k;C=control group.

FIG. 7. Calcium content in aorta after s.c. administration of IP6 in avitamin D-induced cardiovascular calcification model in rat (3×300,000IU/kg).

FIG. 8. (A) Progression of heart calcification and (B) inhibition of theprogression of said calcification after s.c. treatment with 10 and 60mg/kg IP6 on days 5 to 14. 100,000 IU/kg vitamin D was administered ondays 1, 2 and 3.

FIG. 9. (A) Progression of renal calcification and (B) inhibition of theprogression of said calcification after s.c. treatment with 10 and 60mg/kg IP6 on days 5 to 14. 100,000 IU/kg vitamin D was administered ondays 1, 2 and 3.

FIG. 10. Chelation of ionic calcium by IP6. Increasing concentrators ofIP6 were added to a 2.5 mM solution of calcium in 0.15 M NaCl, pH 7.4,and the ionic calcium levels measured.

FIG. 11. Increase in the QTc interval alter bolus and non-bolus typeadministration of IP6.

FIG. 12. IP6 concentrations in human blood after administration for 20minutes via the dialysis circuit.

FIG. 13. Ionic calcium concentrations in human blood afteradministration with IP6 for 20 minutes via the dialysis circuit.

FIG. 14. Synergy between IP6 and the effect of cinacalcet (A) andsevelamer (B).

EXAMPLES

The invention will be illustrated below by way of several testsperformed by the inventors which highlight the specificity and efficacyof the treatment method described.

Example 1 Compatible Combination of IP6 With Other Treatments for RenalImpairment

Objective: to evaluate the compatibility of IP6 with other treatmentsfor renal impairment

Experimental: Wistar rats were treated with IP6 (subcutaneous, s.c.),IP6 (s.c.)+sevelamer (oral), IP6 (s.c.)+cinacalcet (oral), IP6(s.c.)+Vit D (s.c.), IP6 (s.c.)+sodium thiosulfate (s.c.), IP6(s.c.)+ibandronate (s.c.).

Results and Discussion: no significant difference is observed betweenadministration of IP6 alone or concomitantly with another treatment. Itis concluded that concomitant administration of IP6 with othertreatments for renal impairment does not imply compatibility problems.

Example 2 In Vitro Determination of the Affinity of IP6 forHydroxyapatite (HAP)

Objective: the objective of this study is to analyse the affinity of IP6for the target thereof, thereby obtaining a curve for the affinity ofIP6 for HAP.

Experimental: 4 different quantities of HAP were incubated withincreasing concentrations of IP6 at 37° C., pH 7.4, for 4 hours whilestirring continuously. The total quantity of IP6 bound to the surface ofthe target (HAP) was quantified.

Results: a dose-dependent adsorption curve, with saturation at aconcentration of 7.6 μM or higher, was obtained. The maximum adsorptionof IP6 on the HAP surface ranges from 4.8 mg adsorbed when using 300 mgof the target to 6.42 mg when using 25 mg of HAP, and this maximumadsorption is achieved in the presence of 7.6 μM IP6 for 8 hours. Tocharacterise the behaviour of IP6 binding, the EC₅₀ and E_(max) for theadsorption thereof on HAP were calculated. This was performed using anon-linear regression model (Log[agonist] vs. response—slope variable;GraphPad Prism software). The EC₅₀ values calculated were 0.46 μM (25 mgHAP), 0.96 μM (75 mg HAP), 1.22 μM (130 mg HAP) and 2.09 μM (300 mgHAP). E_(max) reached saturation at a value of 6.42 mg/g. The resultsare shown in FIG. 1.

Conclusions: IP6 has a high affinity for HAP and adsorption thereof onHAP crystals increases linearly up to 7.6 μM IP6, at which point theadsorption sites on the HAP surface are saturated.

Example 3 In Vitro Determination of the Binding Kinetics of IP6 to HAP

Objective: to analyse the binding rate of IP6 to HAP.

Experimental: 130 mg HAP was incubated (in triplicate) with 7.6 μM IP6,at 37° C., pH 7.4, for different time intervals while stirringcontinuously.

Results and discussion: rapid binding of IP6 to HAP was observed (FIG.2), with an adsorption maximum being reached at 60 minutes. Around 80%of maximum binding was achieved after 5 minutes.

Example 4 In Vitro Affinity of IP6 for HAP. Release Studies

Objective: to analyse the release rate of IP6 from HAP.

Experimental: 130 mg HAP was incubated in triplicate with 7.6 μM IP6, at37° C., pH 7.4, for different time intervals while stirringcontinuously. Subsequently, the HAP with adsorbed IP6 was placed in anIP6-free solution and the amount of IP6 released from the surfacethereof evaluated at different timepoints.

Results and discussion: a relatively slow release of IP6 from the HAPsurface was observed (FIG. 3). After incubation for 2 days, 80% of theIP6 remained bound to the HAP surface.

Example 5 Pharmacokinetic (PK) profile for IP6 administeredsubcutaneously (s.c.) to rats with normal kidney function and withdiminished kidney function.

Objective: to evaluate the PK profile for rats with normal kidneyfunction and renal impairment.

Experimental: a single s.c. dose (10 mg/kg) was administered to ratswith normal kidney function. Plasma samples were obtained at differenttimepoints up to 60 minutes. A different group of Wistar rats receivedoral treatment with adenine 800 mg/kg (p.o.) for 10 days to induce renalimpairment. Alpha-calcidol (300 ng/kg) was administered on days 11 and13 and plasma samples were collected at different timepoints up to 60minutes on day 14. The plasma IP6 concentrations were quantified forboth groups.

Results and discussion: the normal Wistar rats presented measurablelevels for at least 30 minutes, with a peak concentration 7.4 μM at 15minutes post-administration. The uraemic rats showed a much lowerexposure, with much lower levels at all timepoints and a peakconcentration of 1.8 μM at 5 minutes post-administration (FIG. 4). Lowerinositol phosphates (IP5, IP4, IP3, IP2, IP1) and inositol were detectedas metabolites.

Conclusions: IP6 exposure in uraemic animals was lower than in normalanimals, with a lower peak concentration for a shorter period of time.This effect is due to a higher metabolic rate in the presence ofuraemia.

Example 6 Pharmacokinetic (PK) Profile for IP6 Administered to Rats WithNormal Kidney Function and With Renal Impairment (Uraemia) by ProlongedInfusion

Objective: to evaluate the PK profile for IP6 in rats with normal kidneyfunction and non-dialysed rats with renal impairment by intravenousinfusion.

Experimental: Wistar rats with normal kidney function were treated dailywith a dose of 10 or 50 mg/kg IP6 by intravenous infusion over 4 h.Plasma samples were obtained at different timepoints up to 4 hours onday 0. The animals were then treated orally with 600 mg/kg (p.o.)adenine for 10 days to induce renal impairment. The animals were treatedwith alpha-calcidol (300 ng/kg) on days 11 and 13 and plasma sampleswere collected at different timepoints up to 4 hours on day 14. Theplasma IP6 levels were quantified for both groups.

Results: the normal rats showed a peak plasma concentration of 8.4 and68.4 μM at a dose of 10 and 50 mg/kg respectively. However, when ratswere made uraemic, the peak concentration achieved at 10 mg/kg was 2.8μM at 30 minutes, although said value decreased to 1.2 μM after 4 hoursdue to the high metabolic rate. The metabolic effect could be partiallyovercome at 50 mg/kg, with a peak plasma concentration of 24.6 μM beingachieved at 4 hours and no decrease in plasma concentration after 30minutes being observed, thus allowing an approximately constantconcentration to be maintained for 3 hours (from hour 1 to hour 4) (FIG.5). Although the final plasma concentration was lower than in normalrats, exposure remains significant and potentially sufficient to beeffective, as explained in subsequent examples.

Conclusions: IP6 exposure in uraemic animals was lower than in normalanimals, with a lower concentration being reached after 4 hours.However, if the dose is sufficiently high, prolonged infusion allowssignificant levels to be achieved for a prolonged period of time,partially overcoming the effect due to the high metabolic rate.

Example 7 Efficacy of IP6 in Calcium-Related Diseases in Animals WithNormal Kidney Function

7a. Inhibition of vit D-induced (75,000 IU/kg×5) cardiovascularcalcification by intravenous administration of IP6.

Objective: to evaluate the efficacy of intravenous IP6 in inhibitingvitamin D-induced cardiovascular calcification in rats.

Experimental: male Sprague Dawley (SD) rats were divided into 7 groupsand IP6 was administered intravenously daily for 14 days at a dose of 0,0.05, 0.1, 0.5, 1, 5 and 10 mg/kg. Calcification was induced by oraladministration of 75,000 IU/kg vitamin D on treatment days 3 to 7.Samples were collected. On day 14 the aortas and hearts of the animalswere collected to quantify calcification.

Results and discussion: administration of vitamin D induced a markedincrease in calcification of the aorta and heart. Intravenousadministration of 0.05 to 0.5 mg/kg IP6 did not affect the mineralcontent of the aorta and heart. However, administration of a dose ofbetween 1 and 10 mg/kg reduced the calcification in both tissues by upto 60% in aorta and 68% in heart (FIG. 6).

7.b. Inhibition of vit D-induced (300,000 IU/kg×3) cardiovascularcalcification by s.c. IP6.

Objective: to evaluate the efficacy of s.c. IP6 for inhibiting vitD-induced cardiovascular calcification in rats.

Experimental: male SD rats were divided into 9 groups. Two of saidgroups (sham and control groups) received s.c. saline 2 ml/kg; 6 groupsreceived s.c. IP6 at a dose of 0.1, 1, 10, 60 and 100 mg/kg (2 ml/kg)and another 35 mg/kg s.c. sodium pyrophosphate, PPi (2 ml/kg). One groupwas treated with a s.c. Alzet pump loaded with 200 mg/ml IP6.Calcification was induced by oral administration of 300,000 IU/kgvitamin D (2 ml/kg) for 3 days starting on treatment day 3. The shamgroup was treated with saline in a similar manner. The calcium contentin heart, aorta and kidneys was determined after treatment for 7 days.

Results and discussion: s.c. IP6 inhibited calcification, with adose-response behaviour being obtained. The minimum dose that produced asignificant effect was 10 mg/kg, which caused the same effect as 28mg/kg pyrophosphate, with IP6 exhibiting a greater potency. Doses of 60and 100 mg/kg exhibited an efficacy of approximately 60%. Treatment byprolonged administration using an Alzet pump resulted in an 85%reduction in calcification (FIG. 7).

Conclusions: s.c. IP6 inhibits aortic calcification in a dose-responsemanner, with an EC₅₀ of 3.75 mg/kg and an E_(max) of 65.5%. PPi exhibitsgood efficacy but at higher doses than IP6. Prolonged administrationusing an Alzet pump led to a significant increase in efficacy.

7.c. Evaluation of IP6 (s.c.) on the progression of vitamin D-inducedvascular calcification (100,000 IU/kg×3) in a rat model for 2 weeks.

Objective: to evaluate the pharmacological profile of IP6 as regards theprogression of vascular calcification.

Experimental: 48 SD rats were treated ×3 with vitamin D (s.c. 100,000IU/kg) to induce tissue calcification. Calcification was allowed toprogress for 5 days, and treatment with 0, 10 or 60 mg/kg IP6 s.c. wasadministered from day 5 until day 14. Calcification of the kidneys andheart was evaluated.

Results and discussion: tissue calcification clearly progressed from day5 to day 14. Treatment with IP6 inhibited the progression of heartcalcification by 100% (FIG. 8) and that of renal calcification by 95%(FIG. 9) at the highest dose. These findings demonstrate for the firsttime that IP6 can prevent calculus growth in vivo, even when saidcalculi are already formed and deposited in tissue.

Example 8 Efficacy of IP6 in Calcium Disorders in Animals With RenalImpairment (Uraemia)

8.a. Nephrectomy and administration of IP6 by i.v. bolus model

Objective: to determine the efficacy of intravenous IP6 in theprevention of tissue calcification in a chronic renal impairment model(⅚ nephrectomised rats).

Experimental: 48 SD rats were ⅚ nephrectomised by complete right lateralnephrectomy and ⅔ partial nephrectomy of the left kidney. 16 animals pergroup were treated intravenously (bolus) with 2 ml/kg saline, 1 mg/kgIP6 or 5 mg/kg IP6. The animals received a phosphate-rich diet (1% Ca,1.2% P) containing 20% lactose. After 8 weeks the aorta, heart andremaining ⅓ kidney were collected and the tissue calcium contentdetermined.

Results and conclusions: no evidence of calcification inhibition wasobserved when the animals were treated with IP6. Although the modelpresents high variability, as only a small percentage of control animalspresented calcification and the surgical procedure is probably not veryhomogeneous, the high metabolic rate in the uraemic animals is thereason for the lack of efficacy.

8.b. Adenine and bolus-type s.c. administration model.

Objective: to determine the efficacy of IP6 in the prevention of tissuecalcification in an animal model of chronic renal impairment (adenine).

Experimental: CKD was induced in 4 groups (n=12) of male Wistar rats byoral (p.o.) treatment with adenine (800 mg/kg/day) dally for 10 days.After treatment with adenine, the rats received alpha-calcidol at a doseof 300 ng/kg (3×/week, p.o.) until day 28. From day 0 until sacrifice(day 28), the animals were treated with a 2 ml/kg s.c., bolus of 0, 3,10 and 30 mg/kg SP6. At each treatment, 3 additional animals wereincluded to evaluate the PL for IP6. After 28 days the aorta, heart andright kidney were collected and the tissue calcium content determined.

Results and conclusions: no evidence of calcification inhibition wasobserved in any of the tissues. Although the model is reproducible andwith consistent tissue calcification, the high metabolic rate of IP6 inuraemic animals is the reason for the lack of efficacy.

8.c. Adenine and non-bolus-type intravascular administration model.

Objective: to determine the efficacy of IP6 as a non-bolus typeadministration in the prevention of tissue calcification in uraemicanimals.

Experimental: CKD was induced in 2 groups (n=12) of male Wistar rats byoral (p.o.) treatment with adenine (600 mg/kg/day) daily for 10 days.After treatment with adenine, the rats received alpha-calcidol at a doseof 300 ng/kg (3×/week, p.o.) until day 28. From day 0 until sacrifice(day 28), the animals were treated with an intravascular infusion of 50mg/kg IP6 or saline for 4 hours. After 28 days the aorta and heart werecollected and the tissue calcium content determined.

Results and conclusions: treatment with IP6 led to an 80% and 85%reduction in average calcification in the aorta and heart respectively.Despite the high metabolic rate, which reduced the plasma IP6 levels by90% by the end of the experiment, prolonged non-bolus typeadministration allowed the metabolic effect to be compensated and theefficacy of IP6 in a calcium disease under uraemic conditions to beproved for the first time.

Example 9 Calcium Chelation by IP6 in Vitro

Objective: to evaluate the ionic calcium chelation potential of IP6.

Experimental: a 2.5 mM of calcium in NaCl 0.15 M, pH 7.40, was pipettedwith increasing concentrations of IP6. The amount of free ionic calciumwas measured potentiometrically using a calcium-selective electrode anda potentiometer.

Results and conclusions: IP6 exhibits a significant ionic calciumchelation ability above 379 μM, The semi-logarithmic representation ofthe dose-response curve (FIG. 10) shows a sigmoid profile, saturating at3788 μM and with an EC₅₀ of 539 μM. These results are shown in FIG. 10.Said concentration is consistent with the levels observed in in vivostudies and explains why the side-effects of IP6 are related tohypocalcaemia (chelation of ionic calcium).

Example 10 Calcium Chelation by IP6 in Vivo

10.1. The effects of IP6 on cardiovascular function after intravascularinfusion in conscious dogs for 2 hours by telemetry.

Objective: to determine the effects of a non-bolus type administrationof IP6 on the electrocardiogram (ECG) and serum ionic calciumconcentrations.

Experimental: 4 male dogs were treated with 3, 10 and 30 mg/kg IP6 byinfusion for 1 h in a Latin square design. A washout period of one weekwas performed between doses. ECGs were measured telemetrically at 1 hand 20 minutes prior to infusion and 5, 15, 30, 45 minutes, 1, 2, 6 and24 h post-infusion. In a second stage, blood samples were taken for PK,tor the same doses, at 20 minutes prior to infusion and 5, 15, 30minutes and 1, 1.5, 2, 3 and 6 h post-infusion. In this case the washoutperiod between doses was 2 days. Total and free calcium in the bloodsamples was also measured.

Results: the state of health, weight, cardiorespiratory function, ECG,body temperature and total and free potassium in blood were relativelyunaffected by infusion of IP6 for 2 h for any dose. The mean blood ioniccalcium concentrations were also unaffected. The peak IP6 levels foundwere 27, 150 and 482 μM for 3, 10 and 30 mg/kg respectively.

Conclusions: infusion of IP6 at a dose of 3, 10 and 30 mg/kg for 2 h hasno negative effects on dogs under the experimental conditions described.

10.2. The effects of IP6 on cardiovascular function after bolus-typeintravenous administration in conscious dogs by telemetry.

Objective: to examine the effects of a bolus-type administration of IP6in serum ionic calcium, ECG and clinical signs in dogs.

Experimental: 4 male dogs, 2 per dose, were injected with 10, 15 and 30mg/kg. Two washout days were introduced between the different doses. TheECGs were recorded telemetrically.

Blood ionic calcium concentrations were determined on different days tothe ECG measurements.

Results and conclusions: at a dose of 10 mg/kg, IP6 has no significanteffects on ECG parameters or ionic calcium concentrations. A mildtachycardia and prolonged QTc interval were observed above 15 mg/kg,becoming significant above 30 mg/kg (FIG. 11). This effect is correlatedwith a 30% decrease in ionic calcium. Hypocalcaemia is the cause of theprolonged QTc interval. These findings, together with those for infusionover 2 h in the previous example, confirm, that IP6 affectshypocalcaemia and prolongs the QTc interval depending on the peak plasmaIP6 concentration as IP6 can chelate ionic calcium. Said effect can becorrected by increasing the administration period by way of a non-bolustype administration.

Example 11 Administration of IP6 Via the Dialysis System

Objective: to establish the dialysability of IP6 in human blood using areal dialysis system and the effect thereof on calcium chelation.

Experimental: 1 litre of human blood obtained from patients undergoingtherapeutic phlebotomy was introduced into a recipient forming a closeddialysis circuit to simulate a real dialysis. Two experiments wereperformed (administration pre- and post-dialyser, both in bypass anddialysis mode), administering IP6 to human blood for 20 minutes whenoutside the recipient (which simulated the animal or human body) andcirculating via the dialysis circuit. The recipient containing 1 litreof whole blood at a controlled temperature of 37° C. is connected to thedialysis apparatus to form a closed circuit. The dialysis apparatus willbe connected for 1 hour (dialysis fluid flow of 500 ml/mm and blood flowof 350 ml/min). Blood samples are collected at different times todetermine the IP6 and ionic calcium levels.

Results and conclusions: administration of IP6 via the dialysis line for20 minutes using a standard dialysis apparatus, simulating the standardclinical procedure, shows that IP6 is not lost via the dialysis membrane(FIG. 12).

Additionally, it is confirmed that IP6 chelates (sequesters) freecalcium (apparatus in bypass model) when said apparatus is placed indialysis mode this negative effect of chelation is overcome as the ioniccalcium levels are restored as a result of the calcium supplied by thedialysis fluid (FIG. 13), thus allowing this new mode of non-bolus orprolonged release type administration via the dialysis system, which isappropriate for product efficacy, as explained in previous examples, andimproves the safety profile, to be established for IP6.

Example 12 Synergistic Effect of IP6 With Other Treatments for RenalImpairment

Objective: to evaluate the potential synergies between the effects ofIP6 and the effects of other treatments for renal impairment.

Experimental: hydroxyapatite (HAP) was crystallised by mixingappropriate concentrations of calcium and phosphate at pH 7.4. Theeffect of cinacalcet and sevelamer was simulated by suitably modifyingthe calcium and phosphate concentrations. The induction period (timerequired for HAP to begin to crystallise) was recorded as the analyticalsignal.

Results and discussion: the induction period for the control experimentwas 8 minutes. When IP6 is added the induction time increasedprogressively to 28 minutes for a concentration of 11.4 μM.Subsequently, IP6 at different concentrations in the range 0-11.4 μM wascombined with a constant simulated concentration of cinacalcet andsevelamer, modifying the calcium and phosphate concentrationsappropriately. The induction time (without IP6) was 14 and 15 minutes,respectively, when the effect of cinacalcet and sevelamer was simulated.As can be seen from FIG. 14, a clear synergistic effect was discoveredwhen IP6 was added.

1. A method for the treatment and/or prevention of a kidneyfailure-related disease in a subject with kidney failure comprisingadministering to a subject in need an effective amount of a medicamentwhich comprises at least one compound of formula I, or a pharmaceuticalacceptable salt thereof:

where: each R₁ to R₁₂ independently represents H, —X, —OX, —NHX, —NX₂,—SX, —OSO₃HX, —OSO₃X₂ or a compound of formula II:

where each X independently represents H, C₁₋₃₀alkyl, C₂₋₃₀alkenyl,C₂₋₃₀alkynyl or Cy₁, where C₁₋₃₀alkyl, C₂₋₃₀alkenyl and C₂₋₃₀alkynyl areindependently optionally substituted by one or more R₁₄ and where Cy₁ isoptionally substituted by one or more R₁₅; Cy₁ represents a carbocyclicor heterocyclic three- to 10-membered ring, which may be saturated,partially unsaturated or aromatic, where said heterocycle has betweenone and four heteroatoms selected from amongst O, S and N, where saidring can be bound to the rest of the molecule via any available C atomand where Cy₁ is optionally fused to between one and four five- orsix-membered rings, each saturated, partially unsaturated or aromatic,carbocyclic or heterocyclic, and where said fused heterocycle maycontain one or two heteroatoms selected from amongst O, N and S; eachR₁₃ independently represents H, C₁₋₃₀alkyl, —NH₂, —NHC₁₋₃₀alkyl or—N(C₁₋₃₀alkyl)₂, where each C₁₋₃₀alkyl is independently optionallysubstituted with one or more halogen, —OH, —CN and —NO₂ groups; and eachR₁₄ and R₁₅ independently represents —OH, C₁₋₃₀alkoxy,C₁₋₃₀alkylthionyl, C₁₋₃₀acyloxy, phosphate, halogen, trihaloC₁₋₃₀alkyl,nitrile or azide, with the condition that at least one of R₁ to R₁₂independently represents a compound of formula II, characterised in thatsaid medicament is administered in a prolonged release form.
 2. Themethod according to claim 1, where: each X independently represents H,C₁₋₃₀alkyl or Cy₁, where C₁₋₃₀alkyl is optionally substituted by one ormore R₁₄ and where Cy₁ is optionally substituted by one or more R₁₅; andeach R₁₄ and R₁₅ independently represents —OH , C₁₋₃₀alkoxy,C₁₋₃₀alkylthionyl, C₁₋₃₀acyloxy, phosphate, halogen, trihaloC₁₋₃₀alkyl,nitrile or azide.
 3. The method according to claim 1, where: each Xrepresents H, C₁₋₃₀alkyl or Cy₁.
 4. The method according to claim 1,where: each X represents H.
 5. The method according to claim 3, where:At least one of radicals R₁, R₃, R₅, R₇, R₉ or R₁₁ independentlyrepresents a compound of formula II:

where each R₁₃ independently represents H, C₁₋₃₀alkyl, —NH₂,—NHC₁₋₃₀alkyl or —N(C₁₋₃₀alkyl)₂, where each C₁₋₃₀alkyl is independentlyoptionally substituted by one or more halogen, —OH, —CN and —NO₂ groups;and R₂, R₄, R₆, R₈, R₁₀ and R₁₂ independently represent H.
 6. The methodaccording to claim 1, where: R₁, R₃, R₅, R₇, R₉ and R₁₁ independentlyrepresent a compound of formula II:

each R₂₃ independently represents H or C₁₋₃₀alkyl, where each C₁₋₃₀alkylis independently optionally substituted by one or more halogen, —OH, —CNand —NO₂ groups; and R₂, R₄, R₆, R₈, R₁₀, and R₁₂ independentlyrepresent H.
 7. The method according to claim 1, where: R₁, R₃, R₅, R₉and R₁₁ independently represent a compound of formula II:

each R₁₃ independently represents H or C₁₋₃₀alkyl; and R₂, R₄, R₆, R₈,R₁₀ and R₁₂ independently represent H.
 8. The method according to claim1, where: R₁, R₃, R₅, R₇, R₉ and R₁₁ independently represent a compoundof formula II:

each R₁₃ independently represents H; and R₂, R₄, R₆, R₈, R₁₀ and R₁₂independently represent H.
 9. A method for the treatment and/orprevention of a kidney failure related disease in a subject with kidneyfailure comprising administering to a subject in need an effectiveamount of a medicament which comprises a composition comprising at leastone compound of general formula I as described in claims 1 to 8 andanother active substance characterised in that said medicament isadministered in a prolonged release form.
 10. The method according toclaim 9, where the active substance is selected form a list comprising acalcimimetic, vitamin, phosphorus chelator, thiosulfate, bisphosphonate,pyrophosphate, citrate, diuretic, antihypertensive andanticholesteraemic agent.
 11. A method for the treatment and/orprevention of a kidney failure-related disease in a subject with kidneyfailure comprising administering to a subject in need an effectiveamount of a medicament which comprises a combined preparation composingat least one compound of general formula I as described in claims 1 to 8and a compound selected from a list comprising a calcimimetic, vitaminB, vitamin D or vitamin K, phosphorus chelator, thiosulfate,bisphosphonate, pyrophosphate, citrate, diuretic, antihypertensive andanticholesteraemic agent separately, simultaneously or sequentially. 12.The method according to any of claims 1, 9 or 11, where the kidneyfailure-related diseases are calcium disorder-related diseases.
 13. Themethod according to any of claims 1, 9 or 11, where the calciumdisorder-related diseases are selected mom the list comprising renallithiasis, cardiovascular calcification, cardiovascular disease,osteoporosis, bone cancer, podagra, calcific tendinitis, calcinosiscutis, rheumatoid arthritis, bone mineral disease, osteomalacia,adynamic bone, calciphylaxis and cardiovascular diseases.
 14. The methodaccording to any of claims 1, 9 or 11, where the medicinal product isfound in a form suitable for parenteral, topical or enteraladministration.